Approached a Woodland Mansion filled with illagers. Nearby was a village with a dozen villagers and an iron golem. Was underprepared, decided to return later. Left the area (roughly 1000 blocks) and returned with appropriate equipment. Villagers were gone. Iron golem was gone. Illagers (Pillagers and Evokers) were gone. Woodland mansion only had regular nighttime mobs. Considering illagers do not respawn, this removed my goal of obtaining "johnny" illagers. Not sure what happened, since villagers and illagers shouldn't despawn.